1. Relevant Field
Embodiments of the present invention relate to x-ray tube targets. More particular, disclosed embodiments relate to targets, and methods of producing targets, having an improved target track for receiving electrons.
2. The Relevant Technology
X-ray devices of all types employ a cathode and an x-ray target, which serves as an anode. A voltage is connected across the cathode and the x-ray target to create a potential difference between the cathode and the x-ray target. Electrons emitted by the cathode are accelerated across the potential and collide with the x-ray target so as to produce x-rays.
The x-ray target must withstand high temperature operating conditions. The x-ray generation process causes the x-ray target to reach operating temperatures, which can be as high as several thousand degrees Celsius. The higher an x-ray device's radiation requirement, or x-ray power, the higher the operating temperature of the x-ray target. Thus, the x-ray target must be constructed from materials that can withstand x-ray generation operating temperatures.
Although all x-ray target materials experience high operating temperatures, the target track experiences the highest operating temperatures because it is the focal point of the x-ray generating process. In some high powered x-ray applications, the operating temperatures surpass the thermo-mechanical limitations of typical target track materials, and the target track can be damaged or even fail completely. Past attempts to overcome thermo-mechanical limitations of the target track include increasing the overall x-ray target size, or rotating the x-ray target at higher rates. These actions focus on spreading the generated heat over a larger surface area to increase heat dissipation.
Larger x-ray target designs and higher rotation rates lead to several undesirable x-ray device characteristics, including: heavier x-ray targets, bigger x-ray tube housings, larger gantries, and slower access time. Moreover, these characteristics pose reliability problems associated with material strength limitations and significantly increase the cost of high powered x-ray devices.